Dual monitors not working on Gigabyte GV-R6870C-1GD

[gtyler]

I had Lion 10.7.2 working with dual monitors on a PNY Geforce 9800GT 1GB card.

I just swapped that out for a Gigabyte GV-R6870C-1GD card.
I have two Acer S201HL Monitors connected via DVI cables.

During the boot up, the monitors are mirrored.
As soon as it gets to the user login screen, the second monitor shuts off.
After I login, the Displays Preferences does not detect the second monitor.
It does show the following:
Acer S210HL Display
1600 x 900
AMD Radeon HD 6870 1024 MB graphics

Anyone know how to fix this?

 

[manHands]

I had Lion 10.7.2 working with dual monitors on a PNY Geforce 9800GT 1GB card.

I just swapped that out for a Gigabyte GV-R6870C-1GD card.
I have two Acer S201HL Monitors connected via DVI cables.

During the boot up, the monitors are mirrored.
As soon as it gets to the user login screen, the second monitor shuts off.
After I login, the Displays Preferences does not detect the second monitor.
It does show the following:
Acer S210HL Display
1600 x 900
AMD Radeon HD 6870 1024 MB graphics

Anyone know how to fix this?

I'm having the same issue with the same card. Hooked up via DVI cable to two Dell 22" monitors. Monitors are mirrored during boot, but 2nd shuts off at login screen. Help!

 

[andreibosco]

You will probably have to set GraphicsEnabler as No in your org.chameleon.boot.plist file. But this will cause some apps to stop working, like DVD Player and Valve games (like Portal 2). Starcraft 2 works fine, so you will have to try it out to see if any important app for you works or not.

<key>GraphicsEnabler</key>
<string>No</string>

 

[manHands]

You will probably have to set GraphicsEnabler as No in your org.chameleon.boot.plist file. But this will cause some apps to stop working, like DVD Player and Valve games (like Portal 2). Starcraft 2 works fine, so you will have to try it out to see if any important app for you works or not.

<key>GraphicsEnabler</key>
<string>No</string>

Well, it worked. But like you said, DVD Player doesn't work now.

Is this the only fix? There has to be something else out there. I have a $200 video card that has 5 display ports, and only one works?

 

[powerpcg5]

Guys, (2) DVI ports will not work. Because the 2nd DVI port is shared with the Display port, (or some geeky explanation like that.)

Okay, bring back GraphicsEnabler to Yes.

Then, what you need to do is connect the 1st monitor to your DVI port (top one).

Then you buy this $3.00 DP to DVI adapter.
viewtopic.php?f=22&t=40788

Connect the DP to either one of your DP ports (you have 2 DP ports). Both of them will work. So now you have (2) monitors working.

If you have a 3rd monitor, try connecting it to the other DP port. It should work (though I haven't tested 3 monitor setups, I just switched the cable to the other DP port and know they both work.) --- so now that's (3) monitors working.

Then you have the HDML port. Buy an HDML to DVI adapter and there's your 4th monitor.

When you check About this Mac, you should now see AMD Radeon 6870 or something like that instead of a generic 6xxx. You'll also find out DVD player now works.

That's it. Here's my System profile, showing a 6870 because GE=Yes. If GE=No, you'll just see 6xxx

6870.png

 

[manHands]

Fantastic, I knew there had to be another solution. I'll get the adapter and cross my fingers. Thank you so much for this post.

 

[gtyler]

Happy to report that the HDMI to DVI cable works flawlessly.
I happen to have one.

Thank you very much for the tip.

 

[matamord]

@thank your for the advice, I will buy a minidisplay to dvi adapter too. I tried the hdmi outpup it works well but doesn't switch off the lcd panel when mac osx shutdown

 

[heythisisdave]

I'm trying to load three monitors with this card but am currently unsuccessful.

I have 2 20" in Rotation and a 30" in landscape (1200x1600 and 2560x1440). Any combination of three monitors on the top end of the video card shuts it down (1 hdmi, 1 duallink dvi, 1 minidp -> dvi) or (2 minidp to DVI and 1 dual link dvi). What's weird is that if I try a minidp to VGA adapter, it works but the color is horrible.

Any thoughts? This is on Lion 10.7.2.

 

[Shakin_Handz]

If you're looking for full size DP to DVI 6 bucks
http://www.ebay.com/itm/New-DP-Disp...502?pt=LH_DefaultDomain_0&hash=item43a95905b6